Hydrogen sulphide alleviates cadmium stress in Trigonella foenum-graecum by modulating antioxidant enzymes and polyamine content.

Cadmium (Cd) toxicity reduces growth and yield of crops grown in metal-polluted sites. Research was conducted to estimate the potential of hydrogen sulphide (H2 S) to mitigate toxicity caused by Cd in fenugreek seedlings (Trigonella foenum-graecum L.). Different concentrations of CdCl2 (Cd1-1 mM, Cd2-1.5 mM, Cd3-2mM) and H2 S (HS1-100 µM, HS2-150 µM, HS3-200 µM) were assessed. Seeds of fenugreek were primed with sodium hydrosulphide (NaHS), as H2 S donor. Seedlings growing in Cd-spiked media treated with H2 S were harvested after 2 weeks. Cd stress affected growth of fenugreek seedlings. Cd toxicity decreased leaf relative water content (LRWC), intercellular CO2 concentration, net photosynthesis, stomatal conductance and transpiration. However, application of H2 S significantly improved seedling morphological attributes by increasing the activity of antioxidant enzymes, i.e. APX, CAT and SOD, in Cd-contaminated soil. H2 S treatment also regulated phenolic and flavonoid content. H2 S-induced biosynthesis of spermidine (Spd) and putrescine (Put) could account for the enhancement of growth and physiological performance of fenugreek seedlings under Cd stress. H2 S treatment also reduced H2 O2 production (38%) and electrolyte leakage (EL, 51%) in seedlings grown in different concentrations of Cd. It is recommended to evaluate the efficacy of H2 S in alleviating Cd toxicity in other crop plants.

Hydrogen sulphide and salicylic acid regulate antioxidant pathway and nutrient balance in mustard plants under cadmium stress.

Cadmium (Cd), a pervasive noxious heavy metal, is a key threat to agricultural system. It is rapidly translocated and has detrimental effects on plant growth and development. Hydrogen sulphide (H2 S) is emerging as a potential messenger molecule for modulating plant tolerance to Cd. Salicylic acid (SA), a phenolic signalling molecule, can alleviate Cd toxicity in plants. The present study investigated the mediatory role of H2 S (100 µM) and SA (0.5 mM), individually and in combination, in modulating antioxidant defence machinery and nutrient balance to impart Cd (50 µM) resistance to mustard. Accumulation of Cd resulted in oxidative stress (TBARS and H2 O2 ), mineral nutrient imbalance (N, P, K, Ca), decreased leaf gas exchange and PSII efficiency, ultimately reducing plant growth. Both H2 S and SA independently attenuated phytotoxic effects of Cd by triggering antioxidant systems, enhancing the nutrient pool, eventually leading to improved photosynthesis and biomass of mustard plants. The positive effects were more pronounced under combined application of H2 S and SA, indicating a synergistic relationship between these two signalling molecules in mitigating the detrimental effects of Cd on nutrient homeostasis and overall health of mustard, primarily by boosting antioxidant pathway. Our findings provide new insights into H2 S- and SA-induced protective mechanisms in mustard plants subjected to Cd stress and suggest their combined use as a feasible strategy to confer Cd tolerance.

Genetic linkage between protein and DNA polymorphisms and antioxidant capacity of Cuminum cyminum L. accessions.

This study aimed to link the genetic variation observed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and random amplified polymorphic DNA (RAPD) analysis among 11 Cuminum cyminum L. accessions, collected from diverse ecogeographical areas in Saudi Arabia, with their antioxidant capacity to better identify potential genotypes for breeding programs for this medicinal spice. SDS-PAGE analysis revealed genetic variation among cumin germplasms and distinct polymorphisms (100%). Protein polymorphisms were identified based on the number of polypeptide bands (288) with molecular weights ranging from 13.85 to 350 kDa, band intensity, the appearance of new bands, and the absence of other bands. RAPD analysis revealed 363 amplified DNA products with a high polymorphism value (98.88%) based on DNA band type (unique, non-unique, and monomorphic), DNA 90 to 1085-bp long, and band intensity. The unweighted pair group method with arithmetic mean clustering based on SDS-PAGE or RAPD and Jaccard's similarity coefficient divided cumin accessions into similar but distinct clusters with respect to their location of collection. The antioxidant potential of cumin accessions based on 1, 1-diphenyl-2-picrylhydrazyl radical scavenging activity, the ß-carotene-linoleate model system, and total phenolic and flavonoid contents revealed distinct variability. These data indicate that cumin is a valuable genetic resource with high antioxidant activity. Additionally, clustering based on antioxidant activity was not identical to that based on SDS-PAGE and RAPD. Data and clustering of SDS-PAGE and RAPD, combined with the high antioxidant capacity of cumin accessions, are important for the efficient use of genetic resources of cumin in breeding strategies and genetic improvement programs.

Comparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and restricted fragment length polymorphism among fenugreek accessions.

Protein and DNA polymorphismswere surveyed among seven accessions of wild fenugreek (Trigonellafoenum-graecum L.) to estimate their genetic diversity and relationships. Samples were obtained from diverse ecogeographical areas in Saudi Arabia and Yemen. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of seed storage protein showed genetic variations among fenugreek germplasms, both quantitatively and qualitatively, generating a total of 168 polypeptide bands with different molecular weights ranging from 4.5 to 300 kDa. Twenty-six of these bands were polymorphic, with a considerable polymorphism value (80.00%). Furthermore, restriction fragment length polymorphism (RFLP) analysis was also employed, which was based on the ability of four restriction enzymes (EagI, EcoRI, FspI, and HindIII) to cleave genomic DNA of the plant materials at specific target nucleotide sequences into different numbers of DNA fragments. RFLP analysis revealed 166 fragments with known sequences and variable lengths ranging from 80 to 4000 bp with a highly degree of polymorphism (88.71%). Data derived from SDS-PAGE or RFLP analyses were used to produce dendrograms, which clustered the studied fenugreek accessions into different groups based on the unweighted pair group method with arithmetic mean (UPGMA). The resulting relationships indicated that these two marker techniques were nearly equivalent, but not identical, with respect to phylogenetic information. In conclusion, SDS-PAGE analysis of seed proteins should be augmented with RFLP analysis of DNA for reliable estimates of genetic diversity among fenugreek germplasms.